Trueing device for grinding wheels

ABSTRACT

A trueing device for grinding wheels, particularly for trueing concave or convex profiles with a rectilinear movement of the trueing tool. The trueing device has a carrier capable of limited rotary movement determined by adjustable stops and has a slide guide extending at right angles to its pivot axis. A slide is guided for movement on the slide guide and carries the trueing tool. A spring is provided which extends parallel to the slide guide and is located therein. Stop elements are secured to opposite ends of the spring and are engaged at each end with the abutment surfaces on the opposite ends of the slide. The spring normally maintains the abutment surfaces in an aligned condition in the mid position. A driving device is provided which includes a driving shaft which is coaxial with the axis of rotation of the carrier and operates the slide via members that convert its rotary action into rectilinear motion.

United States Patent Riihrle 1 TRUEING DEVICE FOR GRINDING WHEELS [72]Inventor: Anton Riihrle, Goeppingen, Germany [73] Assignee: Firma Lohf &Tillipaul, Hamburg,

Germany [22] Filed: Sept. 8, 1970 [21] Appl. No.: 70,305

[52] U.S. Cl ..l25/11 AT [51] Int. Cl. ..B24b 53/06 [58] Field of Search..l25/11 AT [56] References Cited UNITED STATES PATENTS 2,819,708 1/1958Stalia ..125/11 AT 2,479,101 8/1949 Dahl ..125/l1 AT 2,608,189 8/1952Stalia ..125/11 AT Primary Examinerl-Iarold D. WhiteheadAtt0rneyWoodhams, Blanchard and Flynn [451 Aug. 22, 1972 [57] ABSTRACT Atrueing device-for grinding wheels, particularly for trueing concave orconvex profiles with a rectilinear movement of the trueing tool. Thetrueing device has a carrier capable of limited rotary movementdetermined by adjustable stops and has a slide guide extending at rightangles to its pivot axis. A slide is guided for movement on the slideguide and carries the trueing tool. A spring is provided which extendsparallel to the slide guide and is located therein. Stop elements aresecured to opposite ends of the spring and are engaged at each end withthe abutment surfaces on the opposite ends of the slide. The springnormally maintains the abutment surfaces in an aligned condition in themid position. A driving device is provided which includes a drivingshaft which is coaxial with the axis of rotation of the carrier andoperates the slide via members that convert its rotary action intorectilinear motion.

10 Claims, 4 Drawing Figures Patentgd Aug. 22, 1912 V I 3,685,505

5 Sheets-Sheet 1 Patented Aug. 22, 1912 3,685,505

5 Sheets-Sheet z IIYVENTOR 14/1 70 POf/Pl' M, 5w w/ Patented Aug. 22,1972 3,685,505

3 Sheets-Sheet 5 IIY VENTOR All 7 0 80/6915 TRUEING DEVICE FOR GRINDINGWHEELS This invention relates to a trueing device for grinding wheels,for trueing concave or convex profiles with rectilinear movement of thetrueing tool, the device comprising a carrier capable of limited rotarymove ment determined by adjustable stops, and having a slide guideextending at'right angles to its pivot axis, a slide guided for movementon this guide and carrying the trueing tool, a spring parallel to theslide guide and located therein and engaging at each end with abutmentsurfaces on the carrier and also with abutment surfaces on the slide viastop elements which engage over the abutment surfaces of the slide andthe abutment surfaces of the carrier, which in the mid-position arealigned with those of the slide, and which elements by abutment againstall four abutment surfaces hold the slide resiliently in a mid-position,and a driving device which includes a driving shaft which is coaxialwith the axis of rotation of the carrier and operates the slide viamembers that convert its rotary action into rectilinear motion.

In a known trueing device of this type the spring is a compressionspring which is arranged in a bore extending in the longitudinaldirection of the slide. At both ends of the bore are provided hollowscrews on which the spring bears through the intermediary of washers.Concentric with and within the compression spring is provided a rodwhich is guided through the hollow screws and projects beyond both endsof the bore. The ends of the rod are secured in a forked holder which isconnected to the carrier. The ends of the rod are surrounded by spacingbushings which in the mid-position of the slide project into the hollowscrews. The inner ends of the hollow screws form abutment surfaces onwhich the said washers abut in the mid-position of the slide and hencehold the slide resiliently in the midposition;

This arrangement has various disadvantages. In order that the slide maybe held .in its mid-position without any play, it is necessary for thedistance between the abutment surfaces of the two spacing bushings andthe distance between the abutment surfaces of the two distance bushingsto be exactly equal. However, this can be achieved only with difficulty,since this distance depends on the one hand on the length of the twohollow screws and the length of the slide member into which the hollowscrews are screwed, and on the other hand on the width of the forkedpart of the carrier and the actual length of the spacing bushings. Inmany such machine parts it is extremely difficult to machine them soexactly that the distances between the abutment surfaces are in factequal. Even very slight manufacturing tolerances can add up. If it is infact desired to manufacture a trueing device that operates without play,then the lengths of the spacing bushings must in practice be adjusted bygrinding and testing, complete dismantling of part of the device beingnecessary each time. The multiplicity of individual parts that have tobe very accurately manufactured also makes the manufacture of the knowntrueing device expensive. Should it in fact be possible to machine theseindividual parts so accurately that the spacing of the respectiveabutment surfaces is exactly the same, this does not ensure that in themid-position of the slide relative to the carrier the trueing diamond isalso in fact in its mid-position. For accurate trueing it is howevernecessary for the trueing diamond to be capable of such adjustment thatin the mid-position of the slide it is located exactly in the planepassing through the pivot axis of the carrier. Such adjustment isimpossible with the known trueing device, and additional expenditurewould be necessary in providing for such adjustment.

The invention is based on the problem of providing a trueing device ofthe type referred to initially, which is of simpler construction and ischeaper to manufacture, and wherein the slide is held in itsmid-position in spite of large manufacturing tolerances and which alsopermits subsequent adjustment of the slide relative to the pivot axis.

In accordance with the invention this is achieved in that there isprovided in the slide guide a slider which is connected to the slide viaadjusting screws extending in its direction of movement and movable inthe same direction, which slider has an abutment surface at each end andis of a length that corresponds to the spacing of the two abutmentsurfaces on the slide guide of the carrier, the spring being a tensionspring and having its ends connected to the stop elements.

The new trueing device is, in the first place much simpler inconstruction, because spacing bushings, hollow screws and above all aforked holder, such as were necessary in the known device, are absent.Not only because of the reduced number of individual parts, but alsobecause the remaining individual parts require less accuracy in theirmanufacture, is the new device cheaper to manufacture. In particular,owing to the use of the slider, the length of which corresponds to thespacing of the stop surfaces on the slide, greater tolerances inmanufacture are possible and moreover manufacture is simplified. Theslider may be manufactured together with the slide guide, the abutmentsurfaces on both parts being ground in one operation. This ensures thatthe spacing of the abutment surfaces. on the slider is exactly equal tothe spacing of the abutment surfaces on the slide guide, which is of thegreatest importance for operation of the device without play. In thisoperation it is also not necessary for the spacing of the abutmentsurfaces on both sides of the pivot axis to be exactly the same. On thecontrary, owing to the provision of the adjusting screws adjustment ofthe slide relative to the slider can be effected at any time, in suchmanner that the point of the trueing tool takes up any desired position.

Further advantages and details of the invention are explained in thefollowing description of an embodiment with reference to theaccompanying drawings, in which FIG. 1 is a longitudinal sectional viewof a device according to the invention,

FIG. 2 is a cross-section on the line 11-" of FIG. 1,

FIG. 3 is a cross-section on the line Ill-Ill of FIG. 1, and

FIG. 4 is an end view, looking in the direction IV. of FIG. 1, on asmaller scale.

In the drawings, reference numeral 1 indicates a base plate, whichserves for mounting the trueing device on a machine tool. To this baseplate is connected a housing 2 in which a carrier 4 is pivotally mountedthrough the intermediary of a bearing sleeve 3. The carrier 4 has in itsrear side an annular T-groove 5 in which stops 7 in the form of screwsare guided by means of clamping mernber's6 so that they can be shiftedand fixed in position. To the housing 2 is also secured a fixed stop 8.A ring 9 with a graduated scale may serve for setting the device. .Atthe front side of the carrier 4 a slide guide 11 of dovetail shape issecured by means of the screws shown in FIG. 2. 'A slide 12 is movableon the slide guide 11. The slide 12 is connected to an arm 13 whichcarries the trueing tool 14. Instead of one trueing tool, a plurality oftrueing tools for coarse and fine trueing may be secured to the arm inknown manner.

In accordance with the invention there is provided in the slide guide 11a slider 15, which is also movable relative to the slide guide 11 in thedirection of move ment of the slide 12. This slide 15 is formed at bothends with-abutment surfaces16. The slide guide 1 1 also has abutmentsurfaces 17 at both ends. The distance A between'the abutment surfaces16 of the slider 15 and the distance A between the abutment surfaces ofthe slide guide 11 must be exactly equal. For this purpose it isadvantageous during manufacture to mount the slider 15 and the slideguide 17 together and then to machine the abutment surfaces l6, 17 inone opera tion, for example bygrinding. 1

The slider 15 has, on the side facing the slide guide 11, a groove 18 inwhich a tension spring 19 is arranged. The two ends of the tensionspring are con nectedto js'top elements,- which are preferablyconstituted by 20. The pins 20 r'nayhave at their centers recesses 21for engagement bythe ends 19a of the p s f The slider 15 is connected tothe slide l2'via adjusting screws22 engaging its ends. The slide 12 islonger than the slider 15, andis'provided at both ends with end plates23. Each of these end plates has a hole 24 for I the passage of theadjusting screws 22, the heads 22a of which abutthe end plates 23. Byreleasing one adjusting screwa'jnd tightening the other, the slide 12may be adjusted relativeto the slider 15 and hence the trueing tool 14maybe adjusted relative to the pivot axis a-a of the carrier '4.

Preferably'the slideguide' 11 is of the same length as the slide 15'- inwhich case the abutment surfaces 17 are arranged 'to'be at the ends ofthe slide guide 11. This facilitates grinding of the abutment surfaces16, 17

front end ithas, in the example illustrated, a pinion 28 which as shownin FIG. 2 extends around only half the circumference of the shaft. Inthe position shown in FIGS. 1 and 2 the pinion 28 engages with an upperrack 29 connected to the slider 12. Beneath the pivot axis the slide-l2'is provided with a further rack 30. The

drivihg shaft 26 is journalled so as to .be movable in the axialdirection 8, and in the engaged position of the pinion 28 isheld by aspring loaded ball 31 which engages amiular groove 32 in the drivingshaft 26. By shifting the driving shaft in the direction of the arrow Bitspinion 28 can brought out of engagement with the rack 29, the drivingshaft can then be turned It will first be assumed that the slide 12 isin its midposition. In this-mid-position it is held by the spring,l9 andthe pins 20. The pins 20 bear against the abutment surfaces 16 andagainst the abutment surfaces 17. If the driving shaft 26 is now setinrotation by means of the hand crank 27, the whole carrier first swingswith the slide guide, the slide and the trueing tool. The point of thetrueing tool executes a circular motion. This swinging of the carriercontinues until the stop screw 7 connected to the carrier 4 abuts thefixed stop 8. If further pressure is exerted on the hand crank 27, theslide 12 is shifted by the pinion28 and the rack 29, the spring 19opposing this movement. If for example the slide 12 moves to the left inthe direction of the arrow C inFlG. 3, the left-hand pin 20 moves-awayfrom the abutment surface 17 of the slide guide, while it continues tobear against the abutment surface 16 of the slider 15. Conversely, theright-hand pin 20 remains inv contact with the abutment surface 17 ofthe slide guide 11. During the displacement of the slide 12 against thespring force the point of the trueing diamond executes a rectilinearmovement. This continues until the movement of the slide is stoppedeither by its end plate 23 coming into contact with the slide guide, orby an adjustable stop screw 33 which coacts with a nose 340m the slide12.

If now the hand crank 27 is moved in the opposite direction, the slideis first returned to its mid-position under the action of the tensionspring 19. Only when the slide has again reached its mid-position doesswinging of the carrier occur until the second adjustable stop screw 7aabuts the fixed stop 8 and the slide is then shifted again by the pinion28 and the rack29, against the force of the spring 19, as abovedescribed.

We claim: 1. A trueing device for grinding wheels, comprising: basemeans; first limit means mounted on said base means; carrier meansmounted on said base means and including means for supporting saidcarrier means for rotation relative to said base means, said carriermeans having second limit means thereon enelongated slider means offinite length mounted on said guide for sliding movement therealo'ngiand having means defining second abutment sur.--

faces thereon;

gear transmission means connecting said shaft means to said slidermeans, said gear transmission means being ineffective in moving saidslider means along said guide means on a rotation of said shaft meanswhen said carrier means is free to rotate with said shaft means, saidgear transmission means effecting a movement of said slider means alongsaid guide means when said first and second limit means are engaged; and

stop means engaging said first and second abutment surfaces and adaptedto hold said slider means in a mid-position relative to said guide meanswhen said first and second limit means are out of engagement so that arotation of said shaft means will effect a translational movement ofsaid slider means along said guide means only when said first and secondlimit means are engaged and said shaft means is rotated in a directionto cause said first and second limit means to remain engaged.

2. A trueing device according to claim 1, wherein said guide means andsaid slider means have abutment surfaces on opposite ends; and

wherein said stop means comprise a pair of stop elements positioned toengage said abutment surfaces at opposite ends of said slider means andsaid guide means and tension spring means connected between said pair ofstop elements to hold said stop elements in engagement with said firstand second abutment surfaces on said slider means and said guide means.

3. A trueing device according to claim 2, wherein said elements are pinswhich extend transversely to the direction of pull of said tensionspring means and at their centers have recesses for engagement by theends of said spring means.

4. A trueing device according to claim 1, wherein said guide means is ofthe same length as said slider means.

5. A trueing device according to claim 1, wherein said guide meanscomprises a slide member mounted on said carriage means and a guidemember mounted for translational movement along said slide member, saidslider means being mounted on said guide member for translationalmovement therealong; and

including adjusting means for adjusting the position of said guidemember relative to said slide member.

6. A trueing device according to claim 5, wherein said adjusting meanscomprise adjusting screws and wherein said slide means is longer thansaid slider means and is provided at its ends with end plates, each endplate being formed with a hole for the passage of said adjusting screwthe head of which bears on said end plate.

7. A trueing device according to claim 5, wherein said slider means isguided in a longitudinal groove in said slide member.

8. A trueing device according to claim 5, wherein said slider means hasin the side facing the slide member a groove for the reception of saidspring member.

9. A trueing device according to claim 5, wherein said slide has on eachside of the axis of rotation of said carrier means a rack, said shaftmeans being provided with a pinion extending around half itscircumference, said shaft means being axially shiftable so that thepinion can, by axial movement, be brought out of enae stitawisaarssirsasairtnfls o gr posite direction can be broughtintoengagement with the other rack.

10. A trueing device according to claim 9, wherein said pinion on saidshaft means is held in its engaged position with said rack by a springloaded ball which engages an annular groove in said shaft means.

1. A trueing device for grinding wheels, comprising: base means; firstlimit means mounted on said base means; carrier means mounted on saidbase means and including means for supporting said carrier means forrotation relative to said base means, said carrier means having secondlimit means thereon engageable with said first limit means to limit therotational movement of said carrier means relative to said base means;shaft means mounted on said carrier means for rotation with and withrespect to said carrier means; elongated guide means of finite lengthmounted on said carrier means for movement therewith and having meansdefining first abutment surfaces thereon; elongated slider means offinite length mounted on said guide means for sliding movementtherealong and having means defining second abutment surfaces thereon;gear transmission means connecting said shaft means to said slidermeans, said gear transmission means being ineffective in moving saidslider means along said guide means on a rotation of said shaft meanswhen said carrier means is free to rotate with said shaft means, saidgear transmission means effecting a movement of said slider means alongsaid guide means when said first and second limit means are engaged; andstop means engaging said first and second abutment surfaces and adaptedto hold said slider means in a mid-position relative to said guide meanswhen said first and second limit means are out of engagement so that arotation of said shaft means will effect a translational movement ofsaid slider means along said guide means only when said first and secondlimit means are engaged and said shaft means is rotated in a directionto cause said first and second limit means to remain engaged.
 2. Atrueing device according to claim 1, wherein said guide means and saidslider means have abutment surfaces on opposite ends; and wherein saidstop means comprise a pair of stop elements positioned to engage saidabutment surfaces at opposite ends of said slider means and said guidemeans and tension spring means connected between said pair of stopelements to hold said stop elements in engagement with said first andsecond abutment surfaces on said slider means and said guide means.
 3. Atrueing device according to claim 2, wherein said elements are pinswhich extend transversely to the direction of pull of said tensionspring means and at their centers have recesses for engagement by theends of said spring means.
 4. A trueing device according to claim 1,wherein said guide means is of the same length as said slider means. 5.A trueing device according to claim 1, wherein said guide meanscomprises a slide member mounted on said carriage means and a guidemember mounted for translational movement along said slide member, saidslider means being mounted on said guide member for translationalmovement therealong; and including adjusting means for adjusting theposition of said guide member relative to said slide member.
 6. Atrueing device according to claim 5, wherein said adjusting meanscomprise adjusting screws and wherein said slide means is longer thansaid slider means and is provided at its ends with end plates, each endplate being formed with a hole for the passage of said adjusting screwthe head of which bears on said end plate.
 7. A trueing device accordingto claim 5, wherein said slider means is guided in a longitudinal groovein said slide member.
 8. A trueing device according to claim 5, whereinsaid slider means has in the side facing the slide member a groove forthe reception of said spring member.
 9. A trueing device according toclaim 5, wherein said slide has on each side of the axis of rotation ofsaid carrier means a rack, said shaft means being provided with a pinionextending around half its circumference, said shaft means being axiallyshiftable so that the pinion can, by axial movement, be brought out ofengagement with one rack and after rotation of said shaft means through180* and axial movement in the opposite direction can be brought intoengagement with the other rack.
 10. A trueing device according to claim9, wherein said pinion on said shaft means is held in its engagedposition with said rack by a spring loaded ball which engages an annulargroove in said shaft means.